Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM ENABLING RElY~GTE ANALYSIS of FLUIDS
FIELD 4F THE ~tVENTION
The present invention pextains to the field of fluid analysis and in
particular.to a system
that enables the remote analysis of fluids.
' BACKGROUND
It is desirable that accurate sampling of fluids may be made and understood in
the
context of a man-made and natural fluid systems, such that an estimate of
problems and
potential problems may be. fully understood, while allowing time and
opportunity for
appropriate action to be taken. The collection and analysis of fluids
represents a method
of evaluating the ever-changing natural and constructed environment, and has
'proven to
be a useful way of understanding these systems. The types of fluids presently
collected
include, for example, fresh water, salt water, wastewater and air from the
vicinity of
industrial plants, coal fired hydro-electric plants, water purification
plants, drinking
water facilities arid a variety of other areas as would be readily understood.
. These fluids
1 S can be tested for characteristics including turbidity, temperature, pH
level, dissolved
oxygen, agricultural run-off, phosphorous, nitrogen, metals, toxic organic
compounds,
fecal coliform and other contaminants which may cause problems.
Such fluid systems are often complex and large, and the monitoring of them is
a difficult
task. Currently, the analysis of fluids in remote locations requires a person
to visit the
site when a sample is required. The tester takes a sample, and can generally
return with
the sample to a central laboratory where the fluid is tested. Usually the
tester can collect
many samples from different locations on any one, trip: Alternatively the
tester may take
a portable test unit along, and test the fluid at each location where the
fluid is sampled.
2S When the results of the tests are critical, the tester may use a cell phone
or other means
to relay the test results to a central location.
The use of a human retrieval system has a number of drawbacks. There is a
financial
cost for the time of the tester and method of travel, and with many of these
sites being in
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remote locations, the use of vehicles or aircraft may be required. ,There will
often be a
delay between the sampling and the results of the tests being known if the
samples need
to be returned to the laboratory before being tested. Such delays can cause
difficulties in .
alerting'people to potential problems, and delays in the generation of an
accurate model
for the prediction of future values. Test samples may only be taken at
significant
intervals usually days . or weeks.. Such , long intervals between tests can
cause.
uncertainties and lack of confidence in the sample tests. For example, freak,
unusual ox
incorrect samples may only be checked by a special trip to the test site.
'From time to
time there may be spurious results; as such it would be useful to repeat such
tests to
double-check these strange results. Often a special situation will occur such
as a
weather storm or dam discharge fox example, where tests are required
immediately and
frequently, in order to carefully monitor a potential problem situation. The
use of a
human retrieval system can have significant delay problems ixl such a case.
At the present time, measurements of fluids have focussed on the
identification . of
problems at the . individual points of measurement. There is a need to be able
to
understand the overall system and the interaction between the fluid flow and
the levels
of specific pollutants at the different sites. The human cohection of these
fluid samples
has severely limited the~generation of an bverall model.
At specific times, there is a need for samples of the fluid to be quickly
taken and
retained. For example, after a heavy thunderstorm, there may be a need to take
a sample
of water, which may be analysed by a remote system, but may also be needed for
further
analysis or even as a proof of a pollution quality. Other examples include
the..discharge
of waste material into a water system.
Limited devices are available for the remote analysis of fluids. U.S. Patent
4,09,209
describes a remote water monitoring system, specifically for the collection of
water
samples using a ~ floating buoy. The system has a radio link to a central
location,
whereby requests fox samples to be taken may be made, water samples
subsequently
being taken and tested, and the results of the tests on these samples relayed
back to the
central location. '
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TJ.S. Patent 4,009,078 describes an electroanalytic means of measuring
microorganisms
in a fluid sample. The method uses the changing potential between electrodes
to provide
an estimate of the microorganism content of a sample. Samples of fluid may be
collected, tested, with this collected subsequently being discharged, such
that the system
S is ready fox a new sample to be taken.
The accurate and real time monitoring of fluids can allow for policing of man
made
pollutants in fluids and the assessment of natural changes in the environment
and their
impact on fluid system, for example. Therefore there is a need for a system
that enables
the remote saimpling and testing of fluids for a variety of different
criteria, without the
recalibration or modification of the testing system for each particular test
required.
This background infornlation is provided fox the purpose of making known
information
believed by the applicant to be of possible relevance to the present
invention. No
admission is necessarily intended, nor should be construed, that any of the
preceding
information constitutes prior art against the present invention.
SUMMARY OF THE INVENTION
.An object of the present invention is to provide a system enabling remote
analysis of
fluids. Tn accordance with an aspect of the present invention, there is
provided a system
enabling remote analysis of a fluid, said fluid being collected from at least
one source,
said system comprising a plurality of remote devices capable of collecting and
analyzing
the fluid, each said .remote device including a sample chamber for receiving
and
orienting the fluid for analysis, said sample chamber being in fluidic contact
with one at
Ieast one source, a sensing system operatively associated with fihe sample
ohamber, said
sensing system illuminating the fluid with an encoded illumination signal and
collecting
an illumination response; a signal processing system for. controlling the
sensing system,
said signal processing system performing data analysis procedures for
detecting and
correlating the illumination response with the encoded illumination signal,
thereby
providing a means for determining a fluid spectral response to the
illumination of the
fluid; and a communication module enabling the remote device to transmit
signals; a
central controller for receiving signals from the plurality of remote devices,
said signals
including a plurality of fluid spectral responses, the central controller
collecting the
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signals for subsequent analysis: and at least one communication . network
enabling
transmission of signals between the plurality of remote devices and the
central server.
BRIEF DESCRIPTION OF THE FIGURES
Figure 1 illustrates a distributed system according to one embodiment of the
present
~5 invention, enabling the remote analysis of fluids, including a distributed
network of
remote devices interconnected to a central controller.
Figure 2 illustrates a distributed system according to one embodiment of the
present
invention, wherein the system enables sampling and analysis of .water within a
public
I O water system from an initial source.
Figure 3 illustrates a remote device comprising an optical sensing system and
a signal
processing system according to one embodiment of the present invention.
25 Figure 4 is a schematic of the signal processing system indicating the
interconnectivity
between the elements thereof, according to one embodiment of the present
invention.
Figure 5 illustrates the interrelationship between the key parameters
affecting risk
evaluation performed by the system, according to one, embodiment of the
'present
20 invention.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
The term "fluid" is used to define a plurality of substances that can be a
liquid or a gas
for example, water, oil, natural gas; air, propane and the like.
The term "communication network" . is used to define a plurality of different
communication mechanisms for example, wireless, wired, Ethernet, WAP,
Bluetooth''"',
PSTN, satellite or any other type of communication mechanism as would be
readily
understood by a worker skilled in the art.
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Unless defined otherwise, all technical and scientific terms used herein have
the same
meaning as commonly understood by one of ordinary skill in the art to which
this
invention belongs.
OV,i;'R~LL FL UID .lIfONTORING SYfTEM .
The present invention provides a system enabling the remote analysis of a
fluid, wherein
the analysis of the fluid and collection of data relating thereto can be
provided at a
plurality of remote locations by a plurality of remote devices. Each remote
device is
connected directly or indirectly to a central controller via one or more
communication
networks, thereby enabling centralised collection, evaluation and analysis of
a plurality
of data relating to characteristics of the fluid system being monitored. The
system
according to the present invention can further provide a means for the
collection of
strategic samples of fluid, for example, such that these samples can be
collected from
one or more of the remote locations at a Later time for future and more
detailed analysis
at a laboratory or other facility. The fluid monitoring system provides a
means. for real
time monitoring of a fluid at a plurality of locations together with a global
view of the
characteristics of, a .fluid system. In. one embodiment of the invention,
this, fluid
monitoring system can provide information and risk factors relating to real
time change
in the characteristics of a fluid and the fluid system.
The fluid monitoring system comprises a plurality of remote devices capable of
performing a spectral analysis of a fluid or fluid sample in situ. A remote
device
illuminates a fluid sample with an encoded illumination signal and
subsequently detects
received light comprising information relating to the reaction of the fluid
sample to this
illumination. The reaction of the fluid sample to illumination can be in the
form of
reflectance and/or. fluorescence. The correlation or matching performed
between the
received light and the encoded illumination enhances the detection of the test
sample
reaction, thereby providing a means for identifying the reflectance and/or
fluorescence
reaction of the fluid that may initially be indistinguishable from background
noise within
the system. For example, fluorescence is inherently lower in energy than
reflectance and
hence can be more difficult to detect in the presence of noise. The collection
and
identification of the reaction of a fluid sample to predetermined illumination
can enable
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the determination of a spectral signature of the fluid sample or
characteristics thereof
The fluid monitoring system can have a plurality of remote devices positioned
within the
filuid system, with each performing the functions of data collection and,
analysis. Each
of these remote devices are interconnected to a central controller, thereby,
forming a
network of data collection locations enabling the evaluation of one or more
characteristics including . possible contamination of a fluid within a fluid
movement
system and the location of this possible contamination, for example. The
system can be
used to evaluate characteristics of fluid systems including, for example, a
wafer supply
system, oil,or gas pipeline or the like.
With reference to Figure l, a possible configuration of the fluid monitoring
system is
illustrated. The irzonitoring system .comprises a plurality of remote devices
130, located
a variety of locations. These remote devices are interconnected to the central
controller 1S0 directly or indirectly through one or more communication
networks 140.
In one embodiment, a cluster hub 170 provides an intermediate location for
information
collection and/or analysis that may subsequently transmitted to the central
controller. .In
this manner, the cluster hub provides a means for xeducing demands on the
central
;~ controller far receiving information or even being direotly connected to
remote devices'
in the vicinity of the cluster hub. The cluster hub is subsequently connected
to the
central controller by the same or alternate communication network. Remote
devices are
placed at strategic geographical points where fluid measurement and analysis
is
required. The remote units may be instructed to sample these fluids at defined
times or
may sample continuously or randomly, for example, subsequently relaying the
results to
the central controller directly or indirectly through one or more cluster
hubs. A cluster
~ hub can be used to evaluate and analyse data collected by the remote devices
to which it
is connected and subsequently transmit this analysed information to the
central
controller thereby reducing the volume of data evaluation to be performed by
the centxal
controller: Optionally, a cluster hub may only contact the central controller
if requested
to by the central confiroller or if a predetermined event occurs.
In one embodiment of the present invention, and with reference to Figure 2, a
schematic
of the positioning of components of the fluid monitoring system is provided
having
direct regard to the monitoring of water within a public water system from a
source. In
Figure 2, water from the watershed 11.0 is collected in the public intake 120
associated
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v~iith a water distribution system having piping elements 125 therein for
distributing the
water. A number of remote devices 130 can be positioned within the watershed
110 in
order to evaluate the characteristics of the water prior to entering the water
system and a
number of remote units can be associated with a plurality of locations within
the system
enabling the tracking and evaluation of the water as it passes through the
system.. In
addition, one~or more .remote devices can be positioned at the water outflow
160 in order
to evaluate the quality of the water upon re-entering the environment. This
type of
configuration of the plurality of remote devices can provide a means fox
evaluating and .
determining locations of concern fox water contamination or other' desired or
undesired
characteristics of the water occur. Each of these remote units 130 axe
connected by a
communication network 140 tb a central controller 150, wherein this
communication
network can be the Internet, or other form of communication network, fox
example. The
water autflow 160. defines the path by which the water passes out of the water
distribution system back into the watershed 110. It would be readily
understood by a
worker skilled in the art that the water distribution system can equally be a
natural gas
distribution system or any other type of fluid distribution system for which
there is a
necessity to analyse the characteristics thereof. For example, if the analysis
of a natural
gas distribution system..wera required, the,source would be a natural,gas
field instead o~
a watershed as would be readily understood.
REMOTE DEI~ICES
The fluid monitoring system according to the present invention comprises a
plurality of
remote devices that are remotely located and provide a means for analysing
a,fluid at
desired locations and, subsequently forwarding this information to the central
controller.
Operations performed by a remote device may include taking a sample of fluid,
making
a complete or partial spectral analysis of the fluid and sending the results
to the central
controller
Each remote device comprises a sample chamber, a sensing system, a signal
processing
control system and a communication network system. The sample chamber provides
a
location in which the fluid to be analysed is placed or through which the
fluid to be
analysed flows. The sensing system is operatively associated with the sample
chamber
such that the sensing system is capable of illuminating the fluid in the
sample chamber
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and is capable of detecting the response of the fluid to this illumination.
The signal
processing system provides a means for controlling the sensing system and
hence
controls both the illumination of the fluid and the detection of the response
of the 'fluid
sample. The signal processing system further comprises a weak signal detection
module, which .provides a means fox detecting components of the spectral
response of
the fluid that can typically be masked by noise within the signal processing
system and
the sensing system. The communication network system may be integrated with
the
signal processing system or optionally as a separate module exiabling
communication
between 'the . central controller and the remote device through the use of a
10. communication network. The networking system can be configured to enable a
plurality
of .different networks to interconnect with the remote device, for example,
PSTN,
wireless, hardwired, Ethernet, Internet, local area network and the like. This
type of
interconnection with a communication network can enable the collection of
information
from a plurality of test sites by a central station, thereby potentially
reducing the
personnel required for the collection of this test data. .
As would be known to a worker skilled in the art, depending on the
communication
system (LAN, WAN, ' Internet) by which the iilforlnation from the optical
systems is
transmitted and the desired Level of security desired for the information,
varying levels
of encryption ofthe data may be employed.
With reference to Figure 3, the remote device according to one embodiment of
the
present invention comprising an optical sensing system 7 and a signal
processing
system 5. The remote device comprises: a photonic energy source 15 which is
controlled by the signal processing system 5 (specifically the emitter control
electronics
IO), to emit electromagnetic radiation which can range from ultraviolet to far
infrared
(or a bandwidth from 100 nm to 20000 nm) and optical emission processing means
ZO
which is controlled by the signal processing system 5 (specifically the
emitter control
electronics 10) to receive light from the photonic energy source 15 and to
deliver one or
more illumination wavelengths 22 in an encoded format to a test sample 25. The
optical
emission processing means 20 . can comprise 'a means for isolating one or more
illumination wavelengths and emitter optics .that orient and , focus the
illumination
wavelengths) onto the test sample 25. The remote device further comprises
received
light optical processing means 30 which is controlled by the signal processing
system 5
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(specifically the emitter control electronics 10) to collect and isolate one
or more
wavelengths of received light 2'7 due to the illumination of a test sample 25.
The
received light optical processing means 30 can~comprise detector optics for
collecting
the received light from the test sample 25 and a means for isolating one or
more of the
wavelengths of the received light.. Additionally, the system comprises an
optical
detector 35 to sense and convert to an electrical signal, the received light
which has been
transmitted by the received light optical processing means 30 and a DSP
received signal
processing means 40, which is a component of the signal processing system .5,
to
perform the matched correlation on the output of the~optical detector 35. The
matched
correlation of the received signal is performed based on the received
electrical signals
from the optical detector 35 and encoding parameters from the emitter control
electronics 10 used to encode the illumination wavelengths.
There are various locations for noise or interference to enter the signal
processing
1 S system and the sensing system of the remote device according to the
present invention,
with this interference decreasing the ability to detect signals 'received
from, the test
sample due to its illumination. For example and with further reference to
Figure 3,
ambient light cari enter the sensing system through the received light
optical, processing
means 30 and electrical noise can enter the signal processing system through
the DSP .
received signal processing means 40. The encoding of the illumination signal
and the
matched correlation of the received signal in relation to the encoded
illumination signal
can enable improved detection of the received signals resulting from the
illumination of
the test sample in the presence of noise or interference.
Signal Processing System
The signal processing system provides a means for controlling the sensing
system and
hence controls both .the illumination of the fluid and the detection.of the
response of the
fluid sample. The signal processing system further comprises a weak signal
detection
' module, which provides a means for detecting components of the, spectral
response of
the fluid that can typically be masked by noise within the signal processing
system and
the sensing system.
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In one embodiment Figure 4 illustrates a configuration of the signal
processing system
for integration into a remote device. The signal processing system comprises a
DSP
block IOIO, a transmitter and receiver block 1000, a micro-controller (MCU)
block 1020, a communication block 1030 and a digital and analog power supply
block.
In this embodiment the DSP block comprises a digital signal processing chip
and an
additional external static random access memory (SRA1VI). The DSP block
performs the
computation algoritlnns for fast, real-time processing of spectral data being
transferred
from the optical detector(s). This DSP block also generates signals that are
capable of
modulating the photonic energy source, wherein this modulation signal can be
multiplexed to multiple photonic energy sources if required. However, each
detector, if
there is more than one, has a separate channel into the DSP block for the
transmission of
information relating to the received .light. Tn addition, the DSP block can
control a
optical device that mechanically pulses the illumination radiation for
encoding thereof,
for example, a chopper. As would be known to a worker skilled in the art,
the~required
processing speed of the DSP chip can be determined by the estimated amount and
frequency of the incoming data that is to be processed, for example. In this
manner an
appropriate chip can be determined based 'on xts processing .speed, for
example the .
number ofHertz that the DSP operates, 40 Hz, 60 Hz and so on.
According to this embodiment, the transmitter and receiver block comprises
analog-to-
digital converters) (ADC), digital-to-analog converters) (DAC) and low-pass
filters,
wherein these filters enable anti-aliasing of the received signal. If light
emitting diodes
(LEDs) or laser diodes are used as the photon energy source fox the optical
sensing
system, this block may also comprise a multiplexer and high current
amplifiers. The
multiplexer enables the transmission of signals for the activation of the
multiple
photonic energy sources independently and the high current amplifiers provide
a means
for providing sufficient energy in order to activate these ~photonic energy
sources such
that their maximum spectral power output can be obtained. In one embodiment of
the
present invention, Texas Instruments's CODECs (coder/decoder), TLV320AIC20 and
TLV320AICI0 are used as the analog to digital converters. In this example the
TLV320AIC20 comprises two analog to digital converters and two digital to
analog
converters and the TLV320AIC10 comprises one analog to digital converter and
one
digital to analog converter. Thus by the incorporation of these two CODECs
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stand alone signal processing system; there is provided 3 independent input
and output
channels.
In this embodiment a communication block is integrated into .the signal
processing
system and comprises a networking card, for example, an Ethernet chip or a
wireless
network . chip, which enables the interconnection of the ~ remote device to a
communication network, for example a local area network (LAN), a wide area
network
(WAN) or a wireless network (for example BluetoothTM or IEEE 802.11). A worker
skilled in the art would understand the format and type of chip or card that
is required
for the desired network connection. In addition the communication block
further
comprises a serial interface chip, for example a ~RS-232 port which can
provide a serial
interface to another component or system, for example a computer or a, serial
modem,
for example dial-up or wireless type modem or a, serial connection to a
monochromator.
The communication block therefore can provide a means for a computing system
or a
local computing system to access information collected by the signal
processing system
in addition to the amendment or replacement of algorithms that are operating
on the
signal processing system in addition to configuration dafa.
Furthermore,~the micro-controller unit (MCU) block comprises a MCU chip, which
may
be an 8-bit, 16-bit or 32-bit chip, for example, an external SRAM and an
external
FLASH unit. The MCU block manages the DSP block and the communication block,
wherein the MCU block collects processed data from the DSP block and forwards
this
information to the communication block. Optical devices that filter and/or
focus the
illumination. and received light, for example light filters or monochromatoxs,
can be
controlled by the MCU block. The MCU block may additionally performs
statistical
analyses on the data and may possibly activate an alarm setting. For example,
an alarm
setting may be 'activated if the level of fluorescence of the test sample
exceeds a
predetermined Level, wherein this alarm. activation may comprise the automated
collecting of a sample for a more detailed analysis or the notification of
personnel of the
alarm activation. In the case where software updates to the DSP block are
required, for
example the modification of the match correlation procedure, the MCU block can
manage the remote software updates of the DSP code, for example. The type of
MCU
chip incorporated into the MCU block may vary depending on the volume of
information that is to be processed for example, as would be known to a worker
skilled
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in the art. In one embodiment, the MCU chip has an interface enabling it to
control two
precision bi-polar DC motors, wherein the motor interface can be optically
isolated from
the pins of the MCU chip in order to limit the danger of damaging the MCU
chip, for
example. In another embodiment, the MCU chip can have a number of general
output
~ piris that can be used for controlling valves, temperature sensors and the
like. In one
embodimetlt, the programming of the MCU chip can ~be provided by ~an ISP
interface
which can be provided by the communication block as previously.described. In a
further
embodiment of the invention, the MCU block' further comprises a CPLD (complex
programmable logic device) chip and a reset chip, wherein the CPLD is a re-
programmable integrated circuit that contains address decoding logic and board
reset
logic.
The digital and analog power supply block of the signal processing system can
provide
regulated DC power at a variety of levels depending on that required by the
components
of the signal processing system. In one example, the input power to this
system may be
supplied by an unregulated or varying power supply, for example a wall plug.
The
digital and analog power supply block comprises elements that regulate the
input power
and subsequently generate the required analog and digital voltage levels fox
each
component of the signal processing system. As exarm:ples, elements which
enable the
adjustment of the input power comprises transformers, ~AC-DC converters or
.any other
power regulation element as would be known to a worker skilled in the art.
The signal processing system a variety of software operating thereon, wherein
this is
typically called firmware, which provides the signal processing system with
its
. functionality. It would be readily understood to a worker.skilled in the art
that some of
this fcrmware may or may not be present on any one configuration of the signal
processing system, wherein required firmware can be determined based on the
desired
functionality of a particular signal processing system. For example;
functionality of the ,
firmware which can be running on the signal processing system can.be selected
from the
group comprising: signal transmission and detection based on a desired coding
function,
for example $PSK principals; FIR filtering used to perform the initial clean
up of the
received coded pulses of photonic energy; autocorrelation to perform the
secondary
clean up of the received coded pulses; signal to noise estimation based on
autocorrelation results; microcontroller/DSP ~ communication interface
software;
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microcontrollerlserial port communication interface software; software drivers
fox the
codecs; microcontroller's loading software designed to read a hex file and
load the DSP
with ~ its contents, for example instructions regarding its ~ functionality;
FPGAICPLD
software designed to create the glue-logic to interface the microcontroller,
the multiple
network controllers and the SRAM chips; microcontroller's driver enabling the
operation of a dial-up modem. , .
A coding function is employed by the emitter control electronics in order to
encode the
illumination signal prior to interaction with the test sample, wherein this
coding function
can be provided by any number of signal modulation techniques. For eXample,
pulse
code software can be used to create a synchronous pulse for direct modulation
of the
signal control device frequency (pulse frequency modulation, PFM). With PFM
the
frequency of the pulses is modulated in order to encode the desired
information. Pulse
code software can be used to create a synchronous pulse for direct modulation
of the
signal control device amplitude (pulse amplitude modulation, PAM), wherein
with PAM
the amplitude of the pulses is modulated in order to encode the desired
information. Tn
addition, pulse code software can be used to create synchronous pulse for
direct
modulation of the signal control device pulse width (pulse width modulation,
PWM)
With PWM the width of the pulses is modulated in order to encode the desired
modulation: Finally the illumination signal may be encoded using a function
generator
to create a fixed synchronous pulse enabling pulse rate and amplitude
modulation, in
addition to a mechanical encoder' driver to create a synchronous pulse far an
indirect
signal modulator, for example a chopper, shutter, galvomirror etc.
In one embodiment of the invention the coding function that is employed by the
emitter
control electronics is binary phase shift keying (BPSK) which is a. digital
modulation
format, BPSK is a modulation technique that can be extremely effective for the
reception of weak signals. ~ Using .BPSK modulation, he phase of the carrier
signal is
shifted 180° in accordance with a digital bit stream. The digital
coding scheme of BPSK
is as follows, a "1" causes a phase transition of the carrier signal
(180°) and a "0" does
not produce a phase transition. Using this modulation technique a receiver
performs a
differentially coherent detection process in which the phase of each bit is
compared to
the phase of the preceding bit. Using BPSK modulation may produce an improved
signal-to-noise advantage when compared to other modulation techniques, for
example
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on-off keying. Other encoding techniques can be employed as would be readily
understood by a worker skilled in the art.
Sample Chanzber~
The sample chamber provides a location in which the fluid to be analysed is
placed or
through which the fluid to be analysed flows, The sensing system is
operatively
associated with the sample chamber such that the sensing system is capable of
illuminating the fluid in the sample chamber and is capable of detecting the
response of
. the fluid to this illumination.
In one embodii~nent of the present invention wherein the test sample is a
flowing fluid,
the sample channber associated with the detection device may be a tube
inserted and
appropriately oriented within the fluid flow wherein this tube within the
sample chamber
provides a means for an optical probe to be oriented therein. For example, a
flange at
the end of the sample chamber could alternatively be used instead of a tube.
Tn this
example the optical probe performs the functions of the sensing system. This
sample
chamber can be designed such that, it minimises the effects, on the flow of
the fluid
therehy potentially.reducing its affects on the 'detected response of the
fluid to its
illumination. The size, in particular the cross sectional area, of the sample
chamber can
be designed such that the surface area of the sample chamber is outside of the
optical
detector's field of view. In this manner, the detection of internal
reflectance from the
sample chamber may be minimised. ~In order to potentially further reduce the
sample
chamber's effect of the response, the surface area of the sample chamber, can
be
fabricated with a non-reflective light absorbing material. Furthermore, in
this
embodiment, the sample chamber can be fabricated such that the optical probe
can be .
removed for cleaning, if desired and subsequently replaced in the same
orientation. A
form of indeicing may be used in order to facilitate the realignment of the
optical probe
upon replacement with in the sample chamber.
In another embodiment, the sample chamber is shaped to ensure the minimal
amount of
backscatter illumination towards the sensors associated with the sensing
system. For
example, an asymmetrical shape fox the sample chamber can be used where the
scatter
off the sample chamber is substantially refocused and diffused towards the
drain
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associated with the sample chamber, with no surfaces directly focusing the
scattered
light towards the sensors. ~ In another embodiment, the shape of the sample
chamber
refocuses and diffuses the scattered illumination towards the vent. As would
be xeadily
understood, there are many other ways of shaping the sample chamber suck that
the
scatted illumination is directed out of the sample chamber, while allowing the
fluids to
flow over the sensors.,
In another embodiment of the invention, wherein the fluid to be evaluated is a
liquid, the
sample chamber is designed to maintain the pressure at a constant level in
order to keep
potential de-gassing from the fluid or at least to maintain such de-gassing as
close to a
constant as possible, thereby. potentially limiting the affect this action has
on the analysis
performed by the remote device. Its configuration can be such that fluid
enters a vertical
stack, wherein gas rises to a vent at the top of the stack and fluid flow
continues down to
the sample chamber. The sample chamber may not have any line of site confact
with the
fluid input and vertical stack to reduce the interference of gas bubbles and
potential
boundary layers, vortices and interfering surfaces of different fluid quality
mixes which
could cause undesirable variations in the detection of the response of the
fluid.
In one embodiment, the sample chamber.is characterized as a chamber that
alloyvs fluid
to flow through it and air to escape from above it. The optical sensors of the
sensing
system can be placed on the lower aspect of the sample chamber in oxder to
provide a
means that as much as possible air has been allowed to escape from above prior
to
coming into range of the sensors. Thus the systems .associated with the sample
chamber
and the fluid transfer system, axe used to reduce hydrodynamic noise.
Additionally, a
fluid exhaust channel may be positioned below the sensoxs in order to allow
for the
clearing of any particulate matter from the sample chamber after testing, for
example.
Furthermore, the fluid exhaust channel can be larger than the fluid intake in
order to
reduce the chances of the fluid exhaust channel becoming fouled.
Flatid Car~trol System Associated with a Remote Device
The fluid control system associated with a remote device provides means for
directing
the fluid to be sampled through remote device while providing other features
including
suspended solid removal, fluid pressure reduction, system cleaning and sample
extraction.
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In one embodiment, the remote devices are designed to scan for, as much as
possible
dissolved particulate, thereby mitigating reflection noise from suspended
solids within a.
fluid sample, from the detected spectral responses. In one embodiment, an
intake filter
.5 can be used to remove coarse particles that might plug or otherwise reduce
the flow of
fluid into end through the remote device. A pump can be run continuously to
ensure as
much as possible, a continuous pressure for sampling procedures and to ensure
air
removal from the fluid. Tn one embodiment, the pump can be a submerged style
of unit
or could also be a suction/jet pump or other style of pump as would be readily
understood.
Iri one embodiment of the invention, the fluid flows from the fluid
distribution network
into a first pressure-reducing valve (PRV) that acts to reduce any variations
or surges in
the fluid supply. This PRV can be positioned at the fluid intake of the remote
device.
The fluid subseguently flows to three areas, with these areas being the
cleaning line, the
sample capture line and the sample chamber fluid feed line, however these
lines axe not
required to be separate wherein a single fluid feed line can be used to direct
fluid to one
or more of these required areas, namely cleaning, sample chamber and sample
capture. .
In one embodiment and having regard to the sample chamber feed line, the fluid
is fed'
into a vertical stack associated with the sample chamber. In this case for
example a
second PRV can reduce the fluid pressure to a pressure predetermined for
supply of the
fluid into the sample chamber. This pressure drop can allow for gas bubbles to
expand
rapidly and be vented and to keep the pressure on the optics of the sensing
system to
below a desired level, for example, 20psi, thereby potentially allowing for
Lower cost
fittings due to the lower pressure, for example..
Tn one embodiments having regard to the cleaning line, the fluid feeds
'directly to the
internal or fluid sensing side face of the optics of the sensing system and is
operated by
an electronically actuated valve system to provide a high pressure fluid jet
onto the face
of the optics in order to provide a means for dislodging any particles that
may have
adhered to the optics. This action of causing a fluid jet to attempt to clean
the optics can
be controlled by the signal processing system, wherein the signal processing
system can
determine if parameters related to the collected information have altered in a
manner
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that these types of readings are not consistent with the fluid being analyzed.
For
example, if the data indicates the changes in the collected information are
not typical of
the fluid type being examinef. If thexe is 'a potential chance of a particle
being adhered
to the aptical surfaces, a fluid jet steam can activated by a signal from the
signal
S processing system through a relay and a signal of the correct power to match
the valve
actuator-requirements can be sent. Fluid jets can also be actuated on a
periodic basis in
order to prevent build up on the surfaces. W one embodiment, there may be a
chemically enhanced method' of dislodging any biological film for example from
the
optics of the sensing system. For. example, in a system used to measure water
in a
filtered water system one additive could be ozone, added by either pumping or
by a
venturi effect °into the wash fluid. Another additive may be a
combination of cleaners
and descalers that would be used to decontaminate and remove any particulate
matter
from the optical surfaces. Another possible additive to the wash cycle is a
fluorescent
dye such as fluorescein, which may be used to calibrate the sensor responses
and
15~ determine the performance levels of the equipment. Fluorescein can be
mixed in a
cleaning solution and when injected into the sensor chamber the equipment can
calibrate .
its own performance characteristics.
rn another embodiment a further fluid Iine feeds to an electronically actuated
valve
system that can automatically dispense a sample based on parameters set by the
signal
processing system. Sample collection and storage for biologically active
samples must
allow for~samples to be maintained within a predetermined temperature range.
This~can
. be achieved by a cooling coil or by using a thermo-electric cooling device.
When a
high-risk event triggers a sample collection process, a valve can open
allowing a sample
to be dispensed from the fluid flow. The sample can be passed through the
carbon filter
or.can be treated as required, and then dispensed into a sample capture
chamber where it
can be stored for additional processing by subsystems, treatment or can be
dispensed
into a bottle to be sent to a laboratory. A number of subsystems can be added
to the
sample collection system. This sample can be kept in the sample capture
chamber
where if is stored until dispensed by an operator, or it can be automatically
discarded to a
drain when. the signal processing sytem determines it will collect a
new,sample, for
example. The sample capture chamber can have a vent to allow for gas to escape
upon
the collection and this vent can also'be connected to a drain, in order to
discard the
sample at a future date if xequired. The selection of a sample to be discarded
can be
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based on age of the sample or other factors as would be readily understood.
The sample
~, collection process and subsystems are required to be used in systems where
the need for
automated sampling is required. In addition, for example, samples that are
treated with
chlorine in drinking water need to be dechlorinated by passing through carbon
filters or
S through the addition of by chemical additives to neutralize the chlorine.
One example of
a commonly used chemical neutralizer is sodium thiosulfate. In another
embodiment,
there may be multiple sample capture chambers interconnected with a remote
device,
wherein the sample capture chambers can range in size, ~ in addition to having
a form of
.cooling apparatus associated therewith.
In a further embodiment, management of the system performance can also be
achieved
using a series of valves that are controlled by the MCU. Sensors can be used
to measure
pressure of the water coming into the system, wherein these pressure sensors
can be
indicators of pump performance in a self reliant system, flow failure in a
dependent,
intake pressure, outlet pressure and pressure difference to measure potential
fouling.
The valves for flow control can be electronically operated, diaphragm,
solenoid, or
mechanical options available widely on the market. A peristaltic pump can also
be used
as a valve and.as a pump. ,
In another embodiment, a ~ subsystem for parasite filtering can automatically
pass a
volume bf water through~a collection filter so that parasites can be captured.
The filter
can be of an approved type for parasite collection and could be managed as
required by
the regulatory approved process. The filter apparatus can be maintained in a
cooled
chamber in order to ensure that these organisms are maintained in a live state
prior to
collection by an operator and subsequent testing.
Risk Reporting
In one embodiment, the remote device can monitor a fluid and can report data
with an
associated risk value for example to the central controller. Risk calculation
metrics can
be used in evaluating the duration, amplitude, frequency and phase of events.
Fox
example, in the case of biological turbidity in a water supply, the system can
report the
risk at any time, as a variable between for 1-9, where 1 would indicate no
risk, and 9
would indicate a very high risk. This reporting can be presented in a weighted
form
1s
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where it can be compared to what is normal and the scale of reporting can be
designed. to
be adaptive to the environment. For instance where events detected by a
predetermined
remote device at a predetermined location occur more often when compared with
another device location, the frequency of events in normal operations can be
recorded
and used as a baseline, for example. An increase in the frequency of
occurrence can
increase the risk. Thus the fatal, risk at a particular point in time might be
xeported as fhe
same.for two different remote devices even if the frequency of events
occurring at these
two locations ~is different.
In one embodiment, the risk can also be dependent upon the weighted value of
responses. Fox instance, a sensor response from an input that only changes
when there is
a significant problem is likely to be given higher priority than a sensor that
would
respond to a wide variety of events. In addition, coincidental responses may
cause a
high level of risk. For example, a turbidity event might not be very
significant if it
contained very little biomatter, however when weighted by a significant
biological event
it would be more important. Furthermore, there may be more risk in a
relatively small
change at particular wavelengths that are related to biomatter than those
related to non-
organic dissolved~solids, for example.
Tn one embodiment of the invention, the functionality of the signal processing
system
inay further comprise the ability of establishing an alarm setting associated
tivith the risk ~~
analysis for example, wherein one or more actions are taken upon the
activation of an
alarm setting. For example, the signal processing system may constantly
correlate and
perform statistical analyses on the processed data and once a predetermined
level of
change in the received light is reached, the signal processing system will
activate the
alarm setting. The activation of an alaru setting may result in a message
being sent to
the central controller. rn one embodiment, wherein the test sample is~ a
flowing fluid
sample,vthe activation of an alarm setting can result in a fluid sample being
extracted
from the fluid flow, through the use of a valve to transfer fluid from the
flow to a
collection container, for example. This fluid sample may subsequently be
subjected to a
detailed analysis for evaluation of its contents at a laboratory, for example.
In the
example of the monitoring of a flowing fluid, the incorporation of an alarm
setting may
enable the capturing of significant changes in the fluid contents by the'
sampling of the
fluid upon the detection of a particular level of change in fluid's reectiox1
to light
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illumination. This procedure can provide an ~ improved evaluation of the
changes in a
fluid's content as opposed to periodic, time based, sampling.of the fluid.
Additional SehsoYs
In one embodiment of the present invention, additional sensors are
incorporated. into a
remote device in order to determine additional qualities of the fluid sample
being tested.
For example a sensors including a pH sensor, a temperature sensor, a chlorine
sensor or
a turbidity sensor; for example. Other sensors can be incorporated into a
remote device
. as would be known to a worker skilled in the art. These sensors can depend
directly on
the fluid being analysed, for example unwanted impurities in natural gas can
be
completely different from those in water and therefore the additional sensors
associated
with a remote device can be used to identify the desired impurities or
contaminants of a
particular fluid.
In one embodiment of the present invention, information collected by
additional sensors
associated with one or more of the remote devices, can be integrated into the
risk
analysis performed by a remote sensor, a cluster hub to which the remote
device is
. connected or the central controller, thereby improving a risk analysis. For
example, .
additional sensors for detecting parameters such as pH, chlorine, temperature
and
turbidity can be used as surrogate predicators of contamination events or of
potential
risk. In one instance, a change is temperature may change ,the ability of
bacteria to
reproduce, or a reduction of chlorine may reduce disinfection. Furthermore, if
for
example, a high degree of chlorine and a high degree of organic material has
been
detected, this may be suggestive of potential condition where
trichloromethanes can be
produced. As would be know to a worker skilled. in the art, xesearch has shown
that this
type of condition has been 'shown to be linked to an increased risk of cancer
and
therefore the detection thereof can be important.
CENTRAL CONTROLLER
The central controller associated with the system of the present invention can
be used to
monitor and further analyse information collected from the remote devices
located at the
remote locations and the cluster hubs, or regional controllers, if integrated
into the fluid
monitoring system. The central controller can be used as a database for the
collected
CA 02518563 2005-09-08
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data and therefore can provide a centralised means for determining statistical
analyses
for the fluid distribution system if desired in order to evaluate trends and
the like of the
entire fluid,system.
In one embodiment of the invention, the central controller server further
comprises a
database. of the remote devices and cluster hubs wherein this database can
comprise the
specifications regarding location, access code, networking capabilities,
communication
network compatibility and any other parameter as would be known to a worker
skilled in
the art, thereby enablinig the central controller to access each remote device
ox cluster
hub to which it is connected.
In one, embodiment, the central controller can send requests to the remote
devices for
additional data, such as more frequent tasting, or to save a ~ sample for
example. In
addition, the central server can be used to yodify the parameters by which the
remote
devices perform the analyses. Tn this manner the central controller can
transmit and/or
amend the firmware associated with the signal processing system of the remote
devices
as would be known to a worker skilled in the art.
In one embodiment of the present invention, when the central contt~oller
determines that
there is a level of risk within the fluid system being monitored, the central
controller
automatically is triggered to send alerts. These alerts can ba sent by any
medium,
including email and mobile devices such as a cell phone. Typical triggers for
alerts may
include: system inactivity for more than 4, hours, determination of a high
risk value,
signal to noise ratio is outside the normal range, power values relating to
collected data
for different channels are v~reaker than normally collected and a sample of a
fluid has
been taken. Other triggers may be implemented based on different needs of
various
users of the fluid monitoring system arid may be conf gured for particular
users.
Predetermined triggers can be sent automatically to a set of previously
defined users,
alerting them of potential problems.
In one embodiment of the present invention, the functionality of the central
controller is
provided by a single computing device, wherein the functionality of each
component of
the system is provided thereby, wherein the components of the system are
embodied as
computer programs executed by the computing device. In an alternate
embodiment, the
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central' controller may comprise a number of computing devices, wherein the
functionality of the system is divided among a collection of computing
devices. In this
embodiment the appropriate computing program or programs which embody the one
or
more components of the system, are installed and executed on the appropriate
S computing device. A. computing device that may be used in association with
this
invention may ~be fox -example a personal computer, a server computer; a main
frame
computer, or a combination thereof, or any other type of .computing device as
would be
known to a worker skilled in the art. Tn the case of multiple computing
devices
performing the functions of the central controller, suitable interface
software and
protocols are integrated thereon as would be readily understood by a worker
skilled in
the art.
CZZCSter Hubs
In one embodiment of the invention there maybe regional central analysis
servers that
provide for the monitoring of a predetermined collection of detection devices.
These
1 S regional central analysis servers can be interconnected together to a main
central
. analysis server .that, only communicates with these regional servers in
order to gather
information. In this manner the collection and analysis of data can be
perforriled on a
tiered system and one particular central analysis server is not overloaded
with the
collection of all of the information collected for the plurality of detection
devices.
Groups of remote units may be networked together in a cluster to be able to
take
advantage of changing conditions in a complex system and could be placed for
instance
in a variety of places such as a watershed, filtration and treatment centres,
storage and
distribution or within the operations of a single control centre such as a
water
25 puri~eation facility. Detector clusters are capable of communication with
each other as
art intelligent community of sensors to allow for enhanced process management.
These
systems would also all link to a detector cluster hub and be capable of
supporting a
larger database for accumulating information that potentially includes health
risk and .
environmental impact data: Sensors in a local network may be clustered to use
one
30 external communications hub to reduce costs.
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Risk Analysis
In one embodiment; various portions of a risk analysis can take place at a
remote device,
the cluster hub and the centz~al controller, wherein each stage becomes a more
global
fluid system analysis. Each unit can have defined rules that enable decisions
to be~made
~, ~on the level of risk to~ be issued at each respective level. .Risk can be
determined from
the measured values and rule-based criteria based on historical data. For
example, the .
turbidity biomass or other multiple input metrics will vary, wherein remote
devices can
monitor this relationship on a continuous basis both using. integrated
intelligence, for
example a rule based system applicable to the fluid being monitored and post
monitoring. Tn one embodiment, the fluid monitoring ~ system is more directed
to value
changes than with absolute values. As an example, risk can be reported as RBC,
Risk of
Biological Contamination as it can be representative of significant changes in
a water
system.
In one embodiment, the risk analysis can be a cluster analysis and related to
the
following, namely, evaluation of data from geospatially different locations,
evaluation of
data at the ~ point of measurement having particular regard to the results
from other
sensors associated with the respective remote device and evaluation of data
within a
database enabling data mining. In this manner the risk analysis can provide a
means for
determining a level of risk for a particular area in a fluid system, a general
risk for the .
entire fluid system and additionally is able to correlate and verify
information collected
from one remote device with a remote device in close proximity. Fax example,
if a first
remote device is positioned downstream of a second remote device, a
contamination
warning determined for the second location and not the first location, this
scenario may
prompt a more detailed analysis be performed at the first remote device that
is down
stream in an effort to collect additional information relating to the
contamination.
Secondly, correlation Between , results frou a particular remote device and
additional
sensors connected thereto can provide a means for evaluating the performance
of the
remote device. And correlation between the detected information from a remote
device.
with historical data can provide means for establishing trends for on a daily,
weekly,
monthly, or yearly basis for example, wherein historical events may occur
after a
predetermined level has been detected.
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Risk , can depend on a wide range of factors including the measurements taken,
the
variation with time of these values, the variation over the geographical
space, the
historical data, and the correlation between past measurements and problem
levels of
contaminants. An example of display of risk representation may be presented as
an
. exponential representation of all of the inputs in, a system. ~ As an
example, the 1
distribution of events could show that a greater number of events 'occur .at a
lovv xisk .
level and that a low number of events could occur at a high-risk value.
According to one embodiment, Figure 7 illustrates the relationship between the
fundamental components involved in the computation of the risk value, and the
generation of the database of information associated with the fluid monitoring
system
that can be associated with the central controller. All activities illustrated
in Figure ~7
take place at the central controller, except for those specifically stated as
being in the
remote devices. The test area and test point configuration 520 can provide the
overall
configuration of . the test area being monitored. This information can include
the
. interrelationship between the test points. For example a wafer test point
may be on a
river down-stream of another test point, wherein this interrelationship
between test
. points within a test area can be important to assist the modelling
associated with a
particular fluid system test area. Based on a particular test area, a
determination is
required for what would constitute a risk 530. Such risk could be' a certain
level of
pollution, whereby specific levels would relate to, for example, levels 'of
pollution 'of
drinking water, or a level of a chemical in a water wastage output from a
manufacturing
plant.
The Historical Database 500 of the measurements can provide the basis for a
statistical
dependency between the test points. The statistical analysis of the historical
measurements 510 uses a mathematical model 540 to determine a time-based
dependency between the measurement points, allowing a prediction from one
state to
another, in order that at any moment in time an accurate estimate may be made
of the
levels of, for example, pollution throughout the test area. As would be
readily be
understood, such a capability is important in enabling the prediction of
future events
which may result in the issuance of warnings of potential problems. Generally
a vast
array.of test points requires a set of rules 560 to provide this form
analysis. This set of
rules allows processing of the data within a reasonable time. Using the
predicted levels
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of particular pollutants, for example, and the risk values previously defined,
alert levels
can be determined, and sent to users via a variety of methods including email,
telephone
or other media, wherein these alerts can allow a range of users to quickly
understand a
potentially problem situation. Additionally, a database specifically for
access by users
.5 can allow the users to determine the different levels pollutions, for
example, throughout
the test area; together with existing and potential risk levels.
Simultaneously, the plurality of remote devices is continuing to provide more
data to the
central controller, wherein this additional data includes new data from
regular testing,
and risk alerts identified by a remote device. The central controller may have
the
capability of sending requests to the remote devices for additional data, such
as more
frequent testing, or to save a sample if the necessity has been determined
during the
' analysis performed by the central controller: The central controller may
also send new
sets of rules to the remote devices for the calculation of risk alerts, if
modifications
thereto are determined to be required.
In one embodiment, the computations performed by the central controller
occurring on
y the database for each npde include checking system integrity, determining
associations
for computing a risk value, determining the necessary sampling parameters and
performing , multinode analysis. Because the nodes collect multiple channels
of data,
multivariate analyses is required for each step in the computations.
In one embodiment, in order to ensure that system integrity has not
deteriorated and
remote devices do not require servicing, a variety of analyses can be
conducted. These
analyses can be conducted for each of the remote devices, as well as the risk
value
provided thereby, to ensure system performance is at an acceptable level. The
integrity
analysis can be conducted using historical data to determine daily, weekly,
monthly and
annual trends .and behaviour. Tests used include basic descriptive statistics,
short and
long-term trend analysis and cyclic analysis. Should the results of the tests
indicate poor
remote device performance a maintenance check can be oxdered.
In one embodiment, risk values can be used to represent the risk or danger in
a fluid
system based on multiple data inputs. Determining how to compute a risk value
from
the remote device can involve a thorough statistical analysis and
classification process.
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The methods 'needed for determining the data associations needed to calculate
risk
values from the data inputs involve a variety of statistical tests including
Manova, T-
tests, correlations, factor analysis; clutter analysis and regression
analysis. These tests
can be performed on the stored data for each remote device. The particular
associations
. 5 . are slightly different for each remote device because each system
performs slightly
differently, 'and the interpretation of a "poor quality" sample may vary from
site to site.
The association of different inputs into the rzsk values changes with system
integrity, so
associations are. checked on a regular basis, and the results are used to
modify the way
the DSP calculates the risk value.
In one embodiment, computations performed by the central controller can also
be
responsible for providing the signal processing system of one or more remote
devices
with a usable set of parameters to determine suitable sampling conditions,
wherein this
form of computation can comprise a statistical analysis of recent and long-
term
probability density functions for the systems. data. Computing sampling
parameters can
require a combination of statistical methods including, analyzing and
modelling
distributions and analyzing basic descriptive statistics. ~ The sampling
parameters can be
transmitted to the signal processing system .for each node where they ark used
to
determine when a sample should be taken. Parameters can be updated frequently
so that'
the sampling criteria is based on recent statistics, for example.
Whexi multiple remote devices are present in the same watershed or other
system, a
multiple node analysis.can be performed. Analyses can be performed to verify
system
performance, and enhance risk calculations. Analysis can be done an the risk
values
. from the remote devices. Methods used for these calculations can include
correlation,
MA.NOVA, regression analysis, cluster analysis, factor analysis, and neural
networks.
Results from the analysis can be used to adjust the computation of sampling
parameters
and associations between risk and the data inputs.
The signal processing system for a remote device is responsible fox several
functions in
addition to the fundamental signal correlation and processing algorithms
necessary to
properly measure the signal for each channel. With the central controller
information
provided to the signal processing system, calculations performed by the
central
.controller and a relation mapping of the input data channels can be used to
generate a
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risk value.. . The risk value can be calculated after data from each of the
input channels
has been updated. The risk value can be essential because it is used to ~
determine
whether samples should be taken. The signal processing system can employ
functions
. that determine whether a sample should be taken or not. The decision can be
based on a
. , .5 wide variety of factors including how recently a sample was taken, how
high the risk.
value is,rthe rate of change of the risk value, shoi~ and' long ~ texm.
predicted signal ~.
behaviour based on trend analysis and seasonal and cyclic analysis.
'VV~hile some of the factors above involve parameters calculated by the
central controller,
others are computed solely by the signal processing system associated with a
remote
device. The parameters used in the sampling decision scheme can coma from two
sources, one being the information provided by the central controller and the
other being
some simple calculations performed by the on-board signal processing system.
Bandwidth limitations may prevent the transfer of all the raw data from each
remote
device to the central controller. Data can be transmitted re~ulartv_ cn a
~nmhinPrl
smoothing and compression scheme designed to compress non relevant data, for
example data indicating no significant change, in order to reduce the bandwith
required
for transmission. ,In this manner,. a decrease in the bandwidth requirement is
xeduced,
while not loosing information relating to significant changes in the fluid
being
monitored. Several schemes are available for this process, such as standard
compression
methods, polynomial interpolation and basic~maans, for example. Each method
involves
a different compression ratio and loss of data, however because of the
frequency of data
transmission the loss is tolerable.
In one embodiment, implementation of the risk analysis is achieved by
following a set of
specific actions. System integrity calculations are performed on a regular
basis allowing
daily data to, be compared with data from similar periods of time in the
historical
database. Long-term trend and cyclic analysis of the data from each channel
for the
system are performed using Fourier analysis, and ARIMA to determine if there
are any
long-term trends present ~ in the fluid system. The risk value ~ can be
intended to be a
single meaningful value that accurately represents the risk inherent in the
fluid passing
through a remote device. The value can lie on a scale from 1 to~9, currently
discrete
values. A value of 1 is the minimum and 9 corresponds to the highest and most
extreme
risk. The risk value may be calculated through a cluster analysis algorithm.
As an
27
CA 02518563 2005-09-08
WO 2004/102163 PCT/CA2004/000387
example, this enables 6 channels of data, 3 turbidity, 3, fluorescent, for
example to be
combined into a single variable. The cluster analysis scheme builds a
meaningful
classification of the different possible inputs into the risk value. The
clustering for each
remote device will be slightly different, this is necessary because there will
be slightly
. 5 different behaviour among the different remote devices, and what may
qualify as an
extreme signal at one remote device may be routine in another. ~ The necessary
sampling
parameters can be calculated assuming recent historical data is a Gaussian
distribution,
the distribution parameters are calculated (mean, variance, etc.) and the
sampling
parameters can be obtained using the fact that for a Gaussian distribution, a
known
10~ percentage of measurements lie within each deviation from the mean. This
allows for
the determination of a threshold value such that only a small percentage of
all
.measurements fall above tit, and hence only the most extreme readings will
trigger the
remote device to sample, provided the additional checks performed on the
remote device
are satisfied, for example. A. neural network can be used to draw meaningful
15 conclusions from multiple remote devices in the same systems. The results
can be used
to verify system integrity, 'to analyze the risk calculations and can be
incorporated into
the calculations.
In aziother embodiment of the rislt analysis, the signal processing system
calculates the
20 risk value based on .a classification scheme determined ~ through , the
database
corziputations. The pararxieters of the particular relationships and clusters
identified by
the cluster analysis algorithm scheme axe updated on a regular basis
via.communications
from the central controller to each remote device. The analysis algorithm run
on the
central controller can generate a set of relations between the data inputs
that can be used
25 to express the data in a single risk variable. The decision scheme can be
used to
determine when to analyse a combination of factors including the rate of risk
increase,
concavity of the ~ risk signal, sampling parameters from the central ,
controller
. computations how recently the sample was taken and short and long term
trends. For
each factor considered, a threshold value can be provided; fox example
calculated by the
30 signal processing system of a remote device or provided by the central
controller
calculations. Should the thresholds for a given condition be exceeded, and a
sample has
not been taken recently, a new sample can be taken.
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WO 2004/102163 PCT/CA2004/000387
The multiple channels collecting raw data need to store it in a form that is
readily
communicable to the central controller due to bandwidth limitations. To
accomplish
this a polynomial interpolation is used. Data from each channel is represented
by the
four coefficients fox the data collected in the channel. ~A mean square error
is also
stored, giving an indication of the quality of the fit. Each point in the fit
has equal
weight. .
For example, there are many possible reasons for the response characteristics
of the fluid
system that will depend on the location of the individual remote device and
its fluid
characteristics. The output of many different biomolecules likely to be
responsive to
mufti-spectral analysis can be characterised, by examining patterns of the
reflective and
fluorescent emissions. This type of analysis can be helpful in removing the
effects of
optical noise from interfering biomolecules such as chlorophyll. By searching
for the
optical emission,of specific peaks and comparing the relative frequency,
amplitude and
duration of events, a relationship of patterns in a continuously variable
stream of matter
can be determined. The change in these patterns can be a key factor in
determining risk.
Further, the relationship of differences from individual remote devices
throughout a
. network can be used to determine the total risk in, an entire fluid system.
As sensors that
depend on light spectroscopy as used in an ori-line system are generally not
specific in
2p nature due to potential spectral interferences and as a result cannot be
used to identify a
specific pathogen, the patterns of change can become more important thanahe
absolute
response from any one remote device. The relative patterns that such remote
devices
record can become more useful than their absolute response at any one time.
An example of this consideration is the relatively high level of fluorescence
that results
from chlorophyll. As such the presence of chlorophyll can dominate some
detection
wavelengths, thus making the system less sensitive to bacterial contamination
than other
wavelengths. This type of situation would ~ typically be recorded in a
received .
illumination pattern as ~ a higher consistent background or longer event
periods but
because the effect of chlorophyll can be measured and accounted fox,
contamination risk
can be weighted to measurement channels that are not affected by chlorophyll.
This
technique could apply to any contaminant that had measurable features and the
weighting of responses from various sensors is an important feature for real
time signal
processing and risk determination. In the case where chlorophyll is expected
to become
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WO 2004/102163 PCT/CA2004/000387
an interfering factor, more measured wavelengths can be dedicated to measuring
its
spectral peaks to determine how its total presence may change with respect .to
other
factors. In such a case, the variations at other wavelengths may take on more
importance. These functions can automatically account for the responselin the
zeal time
systems intelligence. By creating .a .rule based system that accounts for
response .
patterns, remote devices may be capable of responding to simple questions that
may be .
posed, fox example "What organisms are causing the changes in the water?"
Risk is calculated in real time, based on event basis without performing a
high
specificity assay. , A pathogen or total risk fluid audit at each site which
would provide
the biological and chemical review of general fluid quality, and when a rule-
based
system was asked, "What characteristics have changed, when and by how much2",
the
remote device can automatically apply a risk value based on the probability of
contamination. It is on this basis that remote devices can determine when to
take a
sample and the rule-based system determines the risk at any one point in time.
It is the
risk value that determines if a sample is to be collected and stored or sent
to the lab and
how it is to be prioritised in the overall events schedule.
External Znte~face to the System
In one embodiment,. the fluid., monitoring system includes appropriate
interfaces for
access to the information within the system by authorized personnel. For
example there
can be two types of interfaces available, for example a message alert that can
be sent to a
user to warn of a problem or potential problem and secondly an interface
providing a
user access to a database of 'information in order to provide a more detailed
outlook of
the parameters detected within the fluid system being monitored.
., A user requiring information from the database may with appropriate
authority and
passwords, access part of the database. Figure 8 shows a representation of the
interface
system. Generally the user will employ the Internet to access the database via
a firewall
to view recent and historical data, trends, alert messages, alert criteria and
any other
relevant and authorized information. This access is an important aspect of the
system
allowing many people to have access to processed data relevant to their own
particular
CA 02518563 2005-09-08
WO 2004/102163 PCT/CA2004/000387
area of interest. The system has the capability, fox ~ example to allow
questions;
responses and general communication.
As would be known to worker skilled in the art, while this description is
directed
towards the collection of information relating to the analysis of water, the
system
. according to the present invention can equally~.be used fox the remote
analysis of a
plurality of other fluids for example, air within a HVAC system, gas or oil
within a
pipeline system, or the like. A worker skilled in the art would fully
understand the
modifications that would be required in order.to enable the analysis of other
fluids, for
example the modification of the illumination wavelengths in order to enable a
desired
analysis of the fluid that is under consideration.
EXAMPLE: Ref~aote .Device Testing P~~ocedure
As an example, the following defines the potential optical analyses that can
be
performed using remote device incorporated into the fluid monitoring system
according
to the present invention, wherein these analyses are specific to water being
the fluid
being monitored. For example, the detection of turbidity in water can be based
on
APHA AWWA WEF physical and aggregate properties method 2130. B .nephelometric
and ISO. Turbidity can be a reliable method to determine the total
concentration of
dissolved solids in a continuous manner wherein this can be determined based
on the
~ collection of reflectance data from the water sample. In one embodiment
turbidity can
be measured at 590nm and 840nm and the illumination emitters can be high
performance LED's and the optical emissions can be dispersed from the emitter
lens at
about 20°. The optical detector can view the emitted light path or the
optical normal at a
fixed angle such as 60°. For example the detection of bio-fluorescence
turbidity can be
based on APHA .AWWA WEF physical and aggregate properties method 2130 B
nephelometric. To baseline biological examination for example, method~can be
used in
the laboratory such as for chlorophyll including 10200 H chlorophyll, US EPA
NERL
Method 445Ø Fluorescent turbidity can be used as a method to measure a
surrogate of
the total concentration of dissolved bio matter in a continuous manner,
wherein this can
be based on the detection of fluorescence data from the water sample, In one
embodiment, two channels of bio fluorescence can be used to characterise the
water
flow. The two emitters can be high performance LED's and the optical emissions
can be
3I
CA 02518563 2005-09-08
WO 2004/102163 PCT/CA2004/000387
dispersed from the emitter lens at about 20°. The optical detector can
view the emitted
light path or the optical normal at a fxed. angle such as 60°, for
example. In one
embodiment, long pass filters can be placed in front of the two optical
detectors. Two
channels of turbidity can be measured in with the first emitter at 470nm and a
long pass
filter over the detector optimised for 590nm and the second emitter at 590nm
and a long
pass filter optimised for 640nm. :~ ' ,
The remote detector units are not designed to yield laboratory standard
measurements
but rather a time dependent reference standard documenting what has occurred,
what is
happening and what is likely to be happening at each sensor and each sensor
group.
However, the ability to, gather information in the same manner as accepted by
existing
standards is also a key feature. The ability to duplicate standard laboratory
measurements in the field is generally subject to' the field conditions in
which such
systems operate.~As a result there are opportunities to improve systems
performance and
I5 design.
The remote detector units are designed to be similar to laboratory standard
nephelometers, but with performance capabilities to reduce background
interference and.
noise such as those problems which might be encountered with standard
turbidity
monitors including, bio-fouling, physical fouling, hydrodynamic noise and
buboes,
direct interference from heat, radiation and vibration; electronic
interference ,and
calibration drift. Additionally, remote detector subsystems are designed to
help perform
calibrations and maintenance as well as also automatically engaging in some
laboratory
operations such as sample collection and preparation.
In an example the case of using off the shelf LED emitters, the filters for
excitation and
emission could be as listed below in Table 1, wherein this table indicates a
variety of
spectral characteristics and some of their most likely causes from a bio-
spectroscopy
point of view. ~ The columns labelled Channel 0 and Channel ,1 provide the
filter
characteristics of the detector. .
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WO 2004/102163 PCT/CA2004/000387
Excitation Channel 0 Channel 1
band .
' ~ Filters: Filters:
0 Yellow S l Onm ~I Red 610nm
high pass high pass
Detector Z.Visible 440nm
~ high pass
UV NADH 430nm NA
TX S
320nm - 370nm(Ch 2)
Yel(ow Bio turbidity ' Cyanobacteria
620nm
540nm - 600nmAbsorption and Fluorescence
Reflection
TX 0 , Cytochrome 630nm
Fluorescence
NIR Turbidity Turbidity correction
840nm- 920nmNTU reference standardreference
TX 1 Chlorophyll absorption
peakhpm
Blue Flavins SSOnm FluorescenceCytochrome 630nrrt
440nm- SOOnm Fluorescence
FAD 530nm Fluorescence
.
TX 2
Chlorophyll530nm
.
Fluorescence
TABLE z.
For example, the photonic energy source can be configured with a number of
options to
be wavelength specific or wave band specific depending upon the perceived
risks and
what type of 6io-matter the systems are checking for. For example LED emitters
using
white light can be~ broken into various bands or wavelengths and if more
specificity is
required, the system can be optimized with band specific LED's (such as a blue
LED) ox '
a wavelength specific Iaser diode. Further optical conditioning can be
achieved with
lens systems to reduce stray light or improve collimation and can also be
combined with
optical band pass or interference filters to give greater frequency
specificity arid to
reduce out of band chromatic diffraction noise. The LED emitters are typically
waterproof and. sealed behind an optical window in the same manner as the
sensors.
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WO 2004/102163 PCT/CA2004/000387
The relationship between sensors and emitters is configured in accordance with
a classic
nephelometer as defined to ISO standards so that the optical measurement
performance
can be compared directly to classical turbidity measurements.
The embodiments of the invention being thus described, it will be.obvious that
the same
may be varied in many ways. Such variations are not to be regarded as a
departure from
the spirit and scope of the invention, and all such modifications as would be
obvious to
one skilled in the art are intended to be included within the scope of the
following
claims.
to
34
